1. Field of the Invention
The present invention relates to retroviral protease inhibitors and, more particularly, relates to novel compounds and a composition and method for inhibiting retroviral proteases. This invention, in particular, relates to sulfamic acid derivatives of hydroxyethylamine protease inhibitor compounds, a composition and method for inhibiting retroviral proteases such as human immunodeficiency virus (HIV) protease and for treating a retroviral infection, e.g., an HIV infection. The subject invention also relates to processes for making such compounds as well as to intermediates useful in such processes.
2. Related Art
During the replication cycle of retroviruses, gag and gag-pol gene products are translated as proteins. These proteins are subsequently processed by a virally encoded protease (or proteinase) to yield viral enzymes and structural proteins of the virus core. Most commonly, the gag precursor proteins are processed into the core proteins and the pol precursor proteins are processed into the viral enzymes, e.g., reverse transcriptase and retroviral protease. It has been shown that correct processing of the precursor proteins by the retroviral protease is necessary for assembly of infectious virons. For example, it has been shown that frameshift mutations in the protease region of the precursor gene of HIV prevents processing cf the gag precursor protein. It has also been shown through site-directed mutagenesis of an aspartic acid residue in the HIV protease that processing of the gag precursor protein is prevented. Thus, attempts have been made to inhibit viral replication by inhibiting the action of retroviral proteases.
Retroviral protease inhibition may involve a transition-state mimetic whereby the retroviral protease is exposed to a mimetic compound which binds to the enzyme in competition with the gag and gag-pol proteins to thereby inhibit replication of structural proteins and, more importantly, he retroviral protease itself. In this manner, retroviral replication proteases can be effectively inhibited.
Several classes of compounds have been proposed, particularly for inhibition of proteases, such as for inhibition of HIV protease. Such compounds include hydroxyethylamine isosteres and reduced amide isosteres. See, for example, EP O 346 847; EP O 342,541; Roberts et al, xe2x80x9cRational Design of Peptide-Based Proteinase Inhibitors,xe2x80x9d Science, 248, 358 (1990); and Erickson et al, xe2x80x9cDesign Activity, and 2.8 xc3x85 Crystal Structure of a C2 Symmetric Inhibitor Complexed to HIV-1 Protease,xe2x80x9d Science, 249, 527 (1990).
Several classes of compounds are known to be useful as inhibitors of the proteolytic enzyme renin. see, for example, U.S. Pat. No. 4,599,198; U.K. 2,184,730; G.B. 2,209,752; EP O 264 795; G.B. 2,200,115 and U.S. SIR H725. Of these, G.B. 2,200,115, GB 2,209,752, EP O 264,795, U.S. SIR H725 and U.S. Pat. No. 4,509,198 disclose urea-containing hydroxyethylamine renin inhibitors. G.B. 2,200,115 also discloses sulfamic acid-containing hydroxyethylamine renin inhibitors, and EP 0264 795 discloses certain sulfamic acid-containing hydroxyethylamine renin inhibitors. However, it is known that, although renin and HIV proteases are both classified as aspartyl proteases, compounds which are effective renin inhibitors generally cannot be predicted to be effective HIV protease inhibitors.
The present invention is directed to virus inhibiting compounds and compositions. More particularly, the present invention is directed to retroviral protease inhibiting compounds and compositions, to a method of inhibiting retroviral proteases, to processes for preparing the compounds and to intermediates useful in such processes. The subject compounds are characterized as sulfamic acid derivatives of hydroxyethylamine inhibitor compounds.
In accordance with the present invention, there is provided a retroviral protease inhibiting compound of the formula: 
or a pharmaceutically acceptable salt, prodrug or ester thereof wherein:
R represents hydrogen, alkyl, alkenyl, alkynyl, cycloalkyl, aryl, aralkyl, alkoxycarbonyl, aryloxyalkyl, heteroaryloxyalkyl, aralkoxycarbonyl, alkylcarbonyl, cycloalkylcarbonyl, cycloalkylalkoxycarbonyl, cycloalkylalkanoyl, alkanoyl, aralkanoyl, aroyl, aryloxycarbonyl, aryloxycarbonylalkyl, aryloxyalkanoyl, heterocyclylcarbonyl, heterocyclyloxycarbonyl, heterocyclylalkanoyl, heterocyclylalkoxycarbonyl, heteroaralkanoyl, heteroaralkoxycarbonyl, heteroaryloxycarbonyl, heteroaroyl, hydroxyalkyl, aminocarbonyl, aminoalkanoyl, and mono- and disubstituted aminocarbonyl and mono- and disubstituted aminoalkanoyl radicals wherein the substituents are selected from alkyl, aryl, aralkyl, cycloalkyl, cycloalkylalkyl, heteroaryl, heteroaralkyl, heterocycloalkyl, heterocycloalkyalkyl radicals, or wherein said aminocarbonyl and aminoalkanoyl radicals are disubstituted, said substituents along with the nitrogen atom to which they are attached form a heterocycloalkyl or heteroaryl radical;
Rxe2x80x2 represents hydrogen, radicals as defined for R3 or Rxe2x80x3SO2xe2x80x94 wherein Rxe2x80x3 represents radicals as defined for R3; or R and Rxe2x80x2 together with the nitrogen to which they are attached represent heterocycloalkyl and heteroaryl radicals;
R1 represents hydrogen, xe2x80x94CH2SO2NH2, xe2x80x94CH2CO2CH3, xe2x80x94CO2CH3, xe2x80x94CONH2, xe2x80x94CH2C(O)NHCH3, xe2x80x94C(CH3)2(SH), xe2x80x94C(CH3)2(SCH3), xe2x80x94C(CH3)2(SC6H5), xe2x80x94C(CH3)2(S[O]CH3), xe2x80x94C(CH3)2(S[O]2CH3), alkyl, haloalkyl, alkenyl, alkynyl and cycloalkyl radicals, and amino acid side chains selected from asparagine, S-methyl cysteine and methionine and the sulfoxide (SO) and sulfone (SO2) derivatives thereof, isoleucine, allo-isoleucine, alanine, leucine, tert-leucine, phenylalanine, ornithine, histidine, norleucine, glutamine, threonine, glycine, allo-threonine, serine, O-alkyl serine, aspartic acid, beta-cyanoalanine and valine side chains;
R1xe2x80x2 and R1xe2x80x3 independently represent hydrogen and radicals as defined for R1, or one of R1xe2x80x2 and R1xe2x80x3, together with R1 and the carbon atoms to which R1, R1xe2x80x2 and R1xe2x80x3 are attached, represent a cycloalkyl radical;
R2 represents alkyl, aryl, cycloalkyl, cycloalkylalkyl and aralkyl radicals, which radicals are optionally substituted with a group selected from alkyl and halogen radials, xe2x80x94NO2, xe2x80x94CN, xe2x80x94CF3, xe2x80x94OR9 and xe2x80x94SR9, wherein R9 represents hydrogen and alkyl radicals;
R3 represents alkyl, haloalkyl, alkenyl, alkynyl, hydroxyalkyl, alkoxyalkyl, cycloalkyl, cycloalkylalkyl, heterocycloalkyl, heteroaryl, heterocycloalkylalkyl, aryl, aralkyl, heteroaralkyl, aminoalkyl and mono- and disubstituted aminoalkyl radicals, wherein said substituents are selected from alkyl, aryl, aralkyl, cycloalkyl, cycloalkylalkyl, heteroaryl, heteroaralkyl, heterocycloalkyl, and heterocycloalkylalkyl radicals, or in the case of a disubstituted aminoalkyl radical, said substituents along with the nitrogen atom to which they are attached, form a heterocycloalkyl or a heteroaryl radical, and thioalkyl, alkylthioalkyl and arylthioalkyl radicals and the sulfone and sulfoxide derivatives thereof;
R4 and R5 independently represent hydrogen and radicals as defined by R3 or together with a nitrogen atom to which they are bonded form a heterocycloalkyl or a heteroaryl radical, and thioalkyl, alkylthioalkyl and aryl radicals and the sulfone and sulfoxide derivatives thereof;
R6 represents hydrogen and alkyl radicals;
x represents 1 or 2;
t represents either 0, 1 or 2; and
Y represents O, S and NR15 wherein R15 represents hydrogen and radicals as defined for R3.
A family of compounds of particular interest within Formula I are compounds embraced by Formula II: 
wherein:
R represents hydrogen, alkyl, alkenyl, cycloalkyl, hydroxyalkyl, aryl, aralkyl, aryloxyalkyl, heteroaryloxyalkyl, alkoxycarbonyl, alkoxyalkyl, aralkoxycarbonyl, alkylcarbonyl, cycloalkylcarbonyl, cycloalkylalkoxycarbonyl, cycloalkylalkanoyl, alkanoyl, aralkanoyl, aroyl, aryloxycarbonyl, aryloxycarbonylalkyl, aryloxyalkanoyl, heterocyclylcarbonyl, heterocyclyloxycarbonyl, heterocyclylalkanoyl, heterocyclylalkoxycarbonyl, heteroaralkanoyl, heteroaralkoxycarbonyl, heteroaryloxy-carbonyl, heteroaroyl, aminocarbonyl, aminoalkanoyl, and mono- and disubstituted aminocarbonyl and mono- and disubstituted aminoalkanoyl radicals wherein the substituents are selected from alkyl, aryl, aralkyl, cycloalkyl, cycloalkylalkyl, heteroaryl, heteroaralkyl. heterocycloalkyl, heterocycloalkyalkyl radicals, or where said aminoalkanoyl radical or aminocarbonyl radical is disubstituted, said substituents along with the nitrogen atom to which they are attached form a heterocycloalkyl or heteroaryl radical;
Rxe2x80x2 represents hydrogen and radicals as defined for R3 or R and Rxe2x80x2 together with the nitrogen to which they are attached represent heterocycloalkyl and heteroaryl radical;
R1 represents hydrogen, xe2x80x94CH2SO2NH2, xe2x80x94CH2CO2CH3, xe2x80x94CO2CH3, xe2x80x94CONH2, xe2x80x94CH2C(O)NHCH3, xe2x80x94C(CH3)2(SH), xe2x80x94C(CH3)2(SCH3), xe2x80x94C(CH3)2(SC6H5), xe2x80x94C(CH3)2(S[O]CH3), xe2x80x94C(CH3)2(S[O]2CH3), alkyl, haloalkyl, alkenyl, alkynyl and cycloalkyl radicals, and amino acid side chains selected from asparagine, S-methyl cysteine and methionine and the sulfoxide (SO) and sulfone (SO2) derivatives thereof, isoleucine, allo-isoleucine, alanine, leucine, tert-leucine, phenylalanine, ornithine, histidine, norleucine, glutamine, threonine, glycine, allo-threonine, serine, O-methyl serine, aspartic acid, beta-cyanoalanine and valine side chains;
R2 represents alkyl, aryl, cycloalkyl, cycloalkylalkyl and aralkyl radicals, which radicals are optionally substituted with a group selected from alkyl and halogen radicals, xe2x80x94NO2, xe2x80x94Cxe2x89xa1N, CF3, xe2x80x94OR9, xe2x80x94SR9, wherein R9 represents hydrogen and alkyl radicals;
R3 represents alkyl, haloalkyl, alkenyl, alkynyl, hydroxyalkyl, alkoxyalkyl, cycloalkyl, cycloalkylalkyl, heterocycloalkyl, heteroaryl, heterocycloalkylalkyl, aryl, aralkyl, heteroaralkyl, aminoalkyl and mono- and disubstituted aminoalkyl radicals, wherein said substituents are selected from alkyl, aryl, aralkyl, cycloalkyl, cycloalkylalkyl, heteroaryl, heteroaralkyl, heterocycloalkyl, and heterocycloalkylalkyl radicals, or in the case of a disubstituted aminoalkyl radical, said substituents along with the nitrogen atom to which they are attached, form a heterocycloalkyl or a heteroaryl radical, and thioalkyl, alkylthioalkyl and arylthioalkyl radicals and the sulfone or sulfoxide derivatives thereof;
R4 and R5 independently represent hydrogen and radicals as defined by R3, or together with the nitrogen atom to which they are bonded represent heterocycloalkyl and heteroaryl radicals.
A more preferred family of compounds within Formula II consists of compounds wherein:
R represents hydrogen, alkyl, alkenyl, cycloalkyl, aryl, aralkyl, alkoxycarbonyl, aralkoxycarbonyl, alkylcarbonyl, cycloalkylcarbonyl, cycloalkylalkoxycarbonyl, cycloalkylalkanoyl, alkanoyl, aralkanoyl, aroyl, aryloxycarbonyl, aryloxycarbonylalkyl, aryloxyalkanoyl, heterocyclylcarbonyl, heterocyclyloxycarbonyl, heterocyclylalkanoyl, heterocyclylalkoxycarbonyl, heteroaralkanoyl, heteroaralkoxycarbonyl, heteroaryloxy-carbonyl, heteroaroyl, aryloxyalkyl, heteroaryloxyalkyl, hydroxyalkyl, aminocarbonyl, aminoalkanoyl, and mono- and disubstituted aminocarbonyl and mono- and disubstituted aminoalkanoyl radicals wherein the substituents are selected from alkyl, aryl, aralkyl, cycloalkyl, cycloalkylalkyl, heteroaryl, heteroaralkyl, heterocycloalkyl, heterocycloalkyalkyl radicals, or where said aminocarbonyl or aminoalkanoyl radical is disubstituted, said substituents along with the nitrogen atom to which they are attached form a heterocycloalkyl or heteroaryl radical;
Rxe2x80x2 represents hydrogen and radicals as defined for R3 or R and Rxe2x80x2 together with the nitrogen to which they are attached represent heterocycloalkyl and heteroaryl radical;
R1 represents CH2C(O)NHCH3, C(CH3)2(SCH3), C(CH3)2(S[O]CH3), C(CH3)2(S[O]2CH3), alkyl, alkenyl and alkynyl radicals, and amino acid side chains selected from the group consisting of asparagine, valine, threonine, allo-threonine, isoleucine, tert-leucine, S-methyl cysteine and methionine and the sulfone and sulfoxide derivatives thereof, alanine, and allo-isoleucine;
R2 represents alkyl, cycloalkylalkyl and aralkyl radicals, which radicals are optionally substituted with halogen radicals and radicals represented by the formula xe2x80x94OR9 and xe2x80x94SR9 wherein R9 represents alkyl radicals; and
R3 represents alkyl, haloalkyl, alkenyl, alkoxyalkyl, cycloalkyl, cycloalkylalkyl, heterocycloalkyl, heterocycloalkylalkyl, aryl, aralkyl and heteroaralkyl radicals; and
R4 and R5 independently represent hydrogen, alkyl, cycloalkyl, cycloalkylalkyl, aryl, heteroaryl, aralkyl, heteroaralkyl, heterocycloalkyl and heterocycloalkylalkyl radicals, or R4 and R5 together with the nitrogen atom to which they are bonded from a heterocycloalkyl or heteroaryl radical.
Of highest interest are compounds within formula II wherein
R represents alkoxycarbonyl, aralkoxycarbonyl, alkylcarbonyl, cycloalkylcarbonyl, cycloalkylalkoxycarbonyl, cycloalkylalkanoyl, alkanoyl, aralkanoyl, aroyl, aryloxycarbonyl, aryloxycarbonylalkyl, aryloxyalkanoyl, heterocyclylcarbonyl, heterocyclyloxycarbonyl, heterocyclylalkanoyl, heterocyclylalkoxycarbonyl, heteroaralkanoyl, heteroaralkoxycarbonyl, heteroaryloxy-carbonyl, heteroaroyl, aminocarbonyl, aminoalkanoyl, and mono- and disubstituted aminocarbonyl and mono- and disubstituted aminoalkanoyl radicals wherein the substituents are selected from alkyl, aryl, aralkyl, cycloalkyl, cycloalkylalkyl, heteroaryl, heteroaralkyl, heterocycloalkyl, heterocycloalkyalkyl radicals, or where said aminoalkanoyl radical is disubstituted, said substituents along with the nitrogen atom to which they are attached form a heterocycloalkyl or heteroaryl radical;
Rxe2x80x2 represents hydrogen and radicals as defined for R3 or R and Rxe2x80x2 together with the nitrogen to which they are attached represent heterocycloalkyl and heteroaryl radical;
R1 represents CH2C(O)NHCH3, C(CH3)2(SCH3), C(CH3)2(S[O]CH3), C(CH3)2(S[O]2CH3), methyl, propargyl, t-butyl, isopropyl and sec-butyl radicals, and amino acid side chains selected from the group consisting of asparagine, valine, S-methyl cysteine, allo-iso-leucine, iso-leucine, and beta-cyano alanine side chains;
R2 represents CH3SCH2CH2-, iso-butyl, n-butyl, benzyl, 4-fluorobenzyl, 2-naphthylmethyl and cyclohexylmethyl radicals;
R3 represents propyl, isoamyl, n-butyl, isobutyl, cyclohexyl, cyclohexylmethyl, benzyl and pyridylmethyl radicals; and
R4 and R5 independently represent hydrogen and methyl, ethyl, i-propyl, n-butyl, t-butyl, 1,1-dimethylpropyl and phenyl radicals, or together with the nitrogen atom to which they are bonded form a pyrrolidinyl, piperidinyl, morpholinyl, piperazinyl or Nxe2x80x2-alkylpiperazinyl radical.
Another family of compounds of particular interest within Formula I are compounds embraced by Formula III: 
wherein:
R represents hydrogen, alkoxycarbonyl, aralkoxycarbonyl, alkylcarbonyl, cycloalkylcarbonyl, cycloalkylalkoxycarbonyl, cycloalkylalkanoyl, alkanoyl, aralkanoyl, aroyl, aryloxycarbonyl, aryloxycarbonylalkyl, aryloxyalkanoyl, heterocyclylcarbonyl, heterocyclyloxycarbonyl, heterocyclylalkanoyl, heterocyclylalkoxycarbonyl, heteroaralkanoyl, heteroaralkoxycarbonyl;, heteroaryloxy-carbonyl, heteroaroyl, alkyl, alkenyl, cycloalkyl, aryl, aralkyl, aryloxyalkyl, heteroaryloxyalkyl, hydroxyalkyl, aminocarbonyl, aminoalkanoyl, and mono- and disubstituted aminocarbonyl and mono- and disubstituted aminoalkanoyl radicals wherein the substituents are selected from alkyl, aryl, aralkyl, cycloalkyl, cycloalkylalkyl, heteroaryl, heteroaralkyl, heterocycloalkyl, heterocycloalkyalkyl radicals, or where said aminoalkanoyl radical is disubstituted, said substituents along with the nitrogen atom to which they are attached form a heterocycloalkyl or heteroaryl radical;
Rxe2x80x2 represents hydrogen and radicals as defined for R3 or R and Rxe2x80x2 together with the nitrogen to which they are attached represent heterocycloalkyl and heteroaryl radical;
R1 represents hydrogen, xe2x80x94CH2SO2NH2, xe2x80x94CH2CO2CH3, xe2x80x94CO2CH3, xe2x80x94CONH2, xe2x80x94CH2C(O)NHCH3, xe2x80x94C(CH3)2(SH), xe2x80x94C(CH3)2(SCH3), xe2x80x94C(CH3)2(S[O]CH3), xe2x80x94C(CH3)2(S[O]2CH3), alkyl, haloalkyl, alkenyl, alkynyl and cycloalkyl radicals, and amino acid side chains selected from asparagine, S-methyl cysteine and methionine and the sulfoxide (SO) and sulfone (SO2) derivatives thereof, isoleucine, allo-isoleucine, alanine, leucine, tert-leucine, phenylalanine, ornithine, histidine, norleucine, glutamine, threonine, glycine, allo-threonine, serine, aspartic acid, beta-cyano alanine and valine side chains;
R1xe2x80x2 and R1xe2x80x3 independently represent hydrogen and radicals as defined for R1, or one of R1xe2x80x2 and R1xe2x80x3, together with R1 and the carbon atoms to which R1, R1xe2x80x2 and R1xe2x80x3 are attached, represent a cycloalkyl radical;
R2 represents alkyl, aryl, cycloalkyl, cycloalkylalkyl and aralkyl radicals, which radicals are optionally substituted with a group selected from alkyl and halogen radials, xe2x80x94NO2, xe2x80x94Cxe2x89xa1N, CF3, xe2x80x94OR9 and xe2x80x94SR9, wherein R9 represents hydrogen and alkyl radicals;
R3 represents alkyl, haloalkyl, alkenyl, alkynyl, hydroxyalkyl, alkoxyalkyl, cycloalkyl, cycloalkylalkyl, heterocycloalkyl, heteroaryl, heterocycloalkylalkyl, aryl, aralkyl, heteroaralkyl, aminoalkyl and mono- and disubstituted aminoalkyl radicals, wherein said substituents are selected from alkyl, aryl, aralkyl, cycloalkyl, cycloalkylalkyl, heteroaryl, heteroaralkyl, heterocycloalkyl, and heterocycloalkylalkyl radicals, or in the case of a disubstituted aminoalkyl radical, said substituents along with the nitrogen atom to which they are attached, form a heterocycloalkyl or a heteroaryl radical, and thioalkyl, alkylthioalkyl and arylthioalkyl radicals and the sulfone or sulfoxide derivatives thereof;
R4 and R5 independently represent hydrogen and radicals as defined by R3, or together with the nitrogen atom to which they are bonded represent heterocycloalkyl and heteroaryl radicals.
A more preferred family of compounds within Formula III consists of compounds wherein
R represents an arylalkanoyl, heteroaroyl, aryloxyalkanoyl, aryloxycarbonyl, alkanoyl, aminocarbonyl, mono-substituted aminoalkanoyl; or disubstituted aminoalkanoyl, or mono- or dialkylaminocarbonyl radical;
Rxe2x80x2 represents hydrogen and radicals as defined for R3 or R and Rxe2x80x2 together with the nitrogen to which they are attached represent a heterocycloalkyl or heteroaryl radical;
R1, R1xe2x80x2 and R1xe2x80x3 independently represent hydrogen and alkyl radicals having from 1 to about 4 carbon atoms, alkenyl, alkynyl, aralkyl radicals, and radicals represented by the formula xe2x80x94CH2C(O)Rxe2x80x3 or xe2x80x94C(O)Rxe2x80x3 wherein Rxe2x80x3 represents R38, xe2x80x94NR38R39 and OR38 wherein R38 and R39 independently represent hydrogen and alkyl radicals having from 1 to about 4 carbon atoms;
R2 represents alkyl, cycloalkylalkyl and aralkyl radicals, which radicals are optionally substituted with halogen radicals and radicals represented by the formula xe2x80x94OR9 and xe2x80x94SR9 wherein R9 represents hydrogen and alkyl radicals; and
R3 represents alkyl, haloalkyl, alkenyl, alkynyl, alkoxyalkyl, cycloalkyl, cycloalkylalkyl, heterocycloalkyl, heterocycloalkylalkyl, aryl, aralkyl, neteroaryl and heteroaralkyl radicals; and
R4 and R5 independently represent hydrogen, alkyl, cycloalkyl, cycloalkylalkyl, aryl, heteroaryl, aralkyl, heteroaralkyl, heterocycloalkyl and heterocycloalkylalkyl radicals, or R4 and R5 together with the nitrogen atom to which they are bonded from a heterocycloalkyl or heteroaryl radical.
Of highest interest are compounds of Formula III wherein:
R represents an arylalkanoyl, aryloxycarbonyl, aryloxyalkanoyl, alkanoyl, aminocarbonyl, mono-substituted aminoalkanoyl, or disubstituted aminoalkanoyl, or mono-or dialkylaminocarbonyl radical;
Rxe2x80x2 represents hydrogen and radicals as defined for R3 or R and Rxe2x80x2 together with the nitrogen to which they are attached represent a heterocycloalkyl or heteroaryl radical;
R1, R1xe2x80x2 and R1xe2x80x3 independently represent hydrogen, methyl, ethyl, benzyl, phenylpropyl, xe2x80x94C(O)NH2 and propargyl radicals;
R2 represents CH3SCH2CH2-, iso-butyl, n-butyl, benzyl, 4-fluorobenzyl, 2-naphthylmethyl and cyclohexylmethyl radicals;
R3 represents propyl, isobutyl, isoamyl, n-butyl, cyclohexyl, cyclohexylmethyl, benzyl and pyridylmethyl radicals; and
R4 and R5 independently represent hydrogen and methyl, ethyl, i-propyl, n-butyl, t-butyl, 1,1-dimethylpropyl, cyclohexyl and phenyl radicals, or together with the nitrogen atom to which they are bonded form a pyrrolidinyl, piperidinyl, morpholinyl or piperazinyl radical.
Another family of compounds of particular interest within Formula I are compounds embraced by Formula IV: 
wherein:
R represents hydrogen, alkyl, alkenyl, cycloalkyl, aryl, aralkyl, aryloxyalkyl, heteroaryloxyalkyl, hydroxyalkyl, alkoxycarbonyl, aralkoxycarbonyl, alkylcarbonyl, cycloalkylcarbonyl, cycloalkylalkoxycarbonyl, cycloalkylalkanoyl, alkanoyl, aralkanoyl, aroyl, aryloxycarbonyl, aryloxycarbonylalkyl, aryloxyalkanoyl, heterocyclylcarbonyl, heterocyclyloxycarbonyl, heterocyclylalkanoyl, heterocyclylalkoxycarbonyl, heteroaralkanoyl, heteroaralkoxycarbonyl, heteroaryloxy-carbonyl, heteroaroyl, aminocarbonyl, aminoalkanoyl, and mono- and disubstituted aminocarbonyl and mono- and disubstituted aminoalkanoyl radicals wherein the substituents are selected from alkyl, aryl, aralkyl, cycloalkyl, cycloalkylalkyl, heteroaryl, heteroaralkyl, heterocycloalkyl, heterocycloalkyalkyl radicals, or where said aminoalkanoyl radical is disubstituted, said substituents along with the nitrogen atom to which they are attached form a heterocycloalkyl or heteroaryl radical;
Rxe2x80x2 represents hydrogen and radicals as defined for R3 or R and Rxe2x80x2 together with the nitrogen to which they are attached represent heterocycloalkyl and heteroaryl radical;
R1 represents hydrogen, xe2x80x94CH2SO2NH2, xe2x80x94CH2CO2CH3, xe2x80x94CO2CH3, xe2x80x94CONH2, xe2x80x94CH2C(O)NHCH3, xe2x80x94C(CH3)2(SH), xe2x80x94C(CH3)2(SCH3), xe2x80x94C(CH3)2(SC6H5), xe2x80x94C(CH3)2(S[O]CH3), xe2x80x94C(CH3)2(S[O]2CH3), alkyl, haloalkyl, alkenyl, alkynyl and cycloalkyl radicals, and amino acid side chains selected from asparagine, S-methyl cysteine and methionine and the sulfoxide (SO) and sulfone (SO2) derivatives thereof, isoleucine, allo-isoleucine, alanine, leucine, tert-leucine, phenylalanine, ornithine, histidine, norleucine, glutamine, threonine, glycine, allo-threonine, serine, aspartic acid, beta-cyano alanine and valine side chains;
R2 represents alkyl, aryl, cycloalkyl, cycloalkylalkyl and aralkyl radicals, which radicals are optionally substituted with a group selected from alkyl and halogen radicals, xe2x80x94NO2, xe2x80x94Cxe2x89xa1N, CF3, xe2x80x94OR9, xe2x80x94SR9, wherein R9 represents hydrogen and alkyl;
R3 represents alkyl, haloalkyl, alkenyl, alkynyl, hydroxyalkyl, alkoxyalkyl, cycloalkyl, cycloalkylalkyl, heterocycloalkyl, heteroaryl, heterocycloalkylalkyl, aryl, aralkyl, heteroaralkyl, aminoalkyl and mono- and disubstituted aminoalkyl radicals, wherein said substituents are selected from alkyl, aryl, aralkyl, cycloalkyl, cycloalkylalkyl, heteroaryl, heteroaralkyl, heterocycloalkyl, and heterocycloalkylalkyl radicals, or in the case of a disubstituted aminoalkyl radical, said substituents along with the nitrogen atom to which they are attached, form a heterocycloalkyl or a heteroaryl radical, and thioalkyl, alkylthioalkyl and arylthioalkyl radicals and the sulfone or sulfoxide derivatives thereof;
R4 and R5 independently represent hydrogen and radicals as defined for R3 or together with a nitrogen atom to which they are bonded form a heterocycloalkyl or a heteroaryl radical.
A more preferred family of compounds within Formula IV consists of compounds wherein
R represents hydrogen, alkoxycarbonyl, aralkoxycarbonyl, alkylcarbonyl, cycloalkylcarbonyl, cycloalkylalkoxycarbonyl, cycloalkylalkanoyl, alkanoyl, aralkanoyl, aroyl, aryloxycarbonyl, aryloxycarbonylalkyl, aryloxyalkanoyl, heterocyclylcarbonyl, heterocyclyloxycarbonyl, heterocyclylalkanoyl, heterocyclylalkoxycarbonyl, heteroaralkanoyl, heteroaralkoxycarbonyl, heteroaryloxy-carbonyl, heteroaroyl alkyl, alkenyl, cycloalkyl, aryl, aralkyl, aryloxyalkyl, heteroaryloxyalkyl, hydroxyalkyl, aminocarbonyl, aminoalkanoyl, and mono- and disubstituted aminocarbonyl and mono- and disubstituted aminoalkanoyl radicals wherein the substituents are selected from alkyl, aryl, aralkyl, cycloalkyl, cycloalkylalkyl, heteroaryl, heteroaralkyl, heterocycloalkyl, heterocycloalkyalkyl radicals, or where said aminoalkanoyl radical is disubstituted, said substituents along with the nitrogen atom to which they are attached form a heterocycloalkyl or heteroaryl radical;
Rxe2x80x2 represents hydrogen and radicals as defined for R3 or R and Rxe2x80x2 together with the nitrogen to which they are attached represent heterocycloalkyl and heteroaryl radical;
R1 represents hydrogen, alkyl and alkenyl radicals, and amino acid side chains selected from the group consisting of asparagine, valine, threonine, allo-threonine, isoleucine, tert-leucine, S-methyl cysteine and the sulfone and sulfoxide derivatives thereof, alanine, and allo-isoleucine;
R2 represents alkyl, cycloalkylalkyl and aralkyl radicals, which radicals are optionally substituted with halogen radicals and radicals represented by the formula xe2x80x94OR9 and xe2x80x94SR9 wherein R9 represents hydrogen and alkyl and halogen radicals;
R3 represents alkyl, halalkyl, alkenyl, alkoxyalkyl, cycloalkyl, cycloalkylalkyl, heterocycloalkyl, heterocycloalkylalkyl, aryl, aralkyl, heteroaryl and heteroaralkyl radicals; and
R4 and R5 independently represent hydrogen, alkyl, cycloalkyl, cycloalkylalkyl, aryl, heteroaryl, aralkyl, heteroaralkyl, heterocycloalkyl and heterocycloalkylalkyl radicals, or R4 and R5 together with the nitrogen atom to which they are bonded from a heterocycloalkyl or heteroaryl radical.
Of highest interest are compounds within Formula IV wherein
R represents hydrogen, alkoxycarbonyl, aralkoxycarbonyl, alkylcarbonyl, cycloalkylcarbonyl, cycloalkylalkoxycarbonyl, cycloalkylalkanoyl, alkanoyl, aralkanoyl, aroyl, aryloxycarbonyl, aryloxycarbonylalkyl, aryloxyalkanoyl, heterocyclylcarbonyl, heterocyclyloxycarbonyl, heterocyclylalkanoyl, heterocyclylalkoxycarbonyl, heteroaralkanoyl, heteroaralkoxycarbonyl, heteroaryloxy-carbonyl, heteroaroyl, aminocarbonyl, aminoalkanoyl, and mono- and disubstituted aminocarbonyl and mono- and disubstituted aminoalkanoyl radicals wherein the substituents are selected from alkyl, aryl, aralkyl, cycloalkyl, cycloalkylalkyl, heteroaryl, heteroaralkyl, heterocycloalkyl, heterocycloalkyalkyl radicals, or where said aminoalkanoyl radical is disubstituted, said substituents along with the nitrogen atom to which they are attached form a heterocycloalkyl or heteroaryl radical;
Rxe2x80x2 represents hydrogen and radicals as defined for R3 or R and Rxe2x80x2 together with the nitrogen to which they are attached represent heterocycloalkyl and heteroaryl radical;
R1 represents hydrogen, methyl, propargyl, t-butyl, isopropyl and sec-butyl radicals, and amino acid side chains selected from the group consisting of asparagine, valine, S-methyl cysteine, allo-iso-leucine, iso-leucine, threonine, serine, aspartic acid, beta-cyano alanine, and allo-threonine side chains;
R2 represents CH3SCH2CH2-, iso-butyl, n-butyl, benzyl, 4-fluorobenzyl, 2-naphthylmethyl and cyclohexylmethyl radicals;
R3 represents propyl, isobutyl, isoamyl, n-butyl, cyclohexyl, cyclohexylmethyl, benzyl and pyridylmethyl radicals; and
R4 and R5 independently represent hydrogen and methyl, ethyl, i-propyl, n-butyl, t-butyl, 1,1-dimethylpropyl, cyclohexyl and phenyl radicals, or R4 and R5 together with the nitrogen atom to which they are bonded form a pyrrolidinyl, piperidinyl, morpholinyl or piperazinyl radical.
As utilized herein, the term xe2x80x9calkylxe2x80x9d, alone or in combination, means a straight-chain or branched-chain alkyl radical containing from 1 to about 10, preferably from 1 to 8, carbon atoms. Examples of such radicals include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, pentyl, iso-amyl, hexyl, octyl and the like. The term xe2x80x9calkenylxe2x80x9d, alone or in combination, means a straight-chain or branched-chain hydrocarbon radial having one or more double bonds and containing from 2 to about 18 carbon atoms preferably from 2 to 8 carbon atoms. Examples of suitable alkenyl radicals include ethenyl, propenyl, 1,4-butadienyl, 12-octadecene and the like. The term xe2x80x9calkynylxe2x80x9d, alone or in combination, means a straight-chain hydrocarbon radical having one or more triple bonds and containing from 2 to about 10 carbon atoms, preferably from 2 to 8 carbon atoms. Examples of alkynyl radicals include ethynyl, propynyl, (propargyl), butynyl and the like. The term xe2x80x9calkoxyxe2x80x9d, alone or in combination, means an alkyl ether radical wherein the term alkyl is as defined above. Examples of suitable alkyl ether radicals include methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, iso-butoxy, sec-butoxy, tert-butoxy and the like. The term xe2x80x9ccycloalkylxe2x80x9d, alone or in combination, means a saturated or partially saturated monocyclic, bicyclic or tricyclic alkyl radical wherein each cyclic moiety contains from about 3 to about 8 carbon atoms and is cyclic. The term xe2x80x9ccycloalkylalkylxe2x80x9d means an alkyl radical as defined above which is substituted by a cycloalkyl radical containing from about 3 to about 8, preferably from 3 to 6 carbon atoms. Examples of such cycloalkyl radicals include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl and the like. The term xe2x80x9carylxe2x80x9d, alone or in combination, means a phenyl or naphthyl radical which optionally carries one or more substituents selected from alkyl, alkoxy, halogen, hydroxy, amino, nitro, cyano, haloalkyl and the like, such as phenyl, p-tolyl, 4-methoxyphenyl, 4-(tert-butoxy)phenyl, 4-fluorophenyl, 4-chlorophenyl, 4-hydroxyphenyl, 1-naphthyl, 2-naphthyl, and the like. The term xe2x80x9caralkylxe2x80x9d, alone or in combination, means an alkyl radical as defined above in which one hydrogen atom is replaced by an aryl radical as defined above, such as benzyl, 2-phenylethyl and the like. The term xe2x80x9caralkoxy carbonylxe2x80x9d, alone or in combination, means a radical of the formula xe2x80x94C(O)xe2x80x94O-aralkyl in which the term xe2x80x9caralkylxe2x80x9d has the significance given above. An example of an aralkoxycarbonyl radical is benzyloxycarbonyl. The term xe2x80x9caryloxyxe2x80x9d means a radical of the formula aryl-Oxe2x80x94 in which the term aryl has the significance given above. The term xe2x80x9calkanoylxe2x80x9d, alone or in combination, means an acyl, radical derived from an alkanecarboxylic acid wherein alkane means a radical as defined above for alkyl. Examples of alkanoyl radicals include acetyl, propionyl, butyryl, valeryl, 4-methylvaleryl, and the like. The term xe2x80x9ccycloalkylcarbonylxe2x80x9d means an acyl group derived from a monocyclic or bridged cycloalkanecarboxylic acid such as cyclopropanecarbonyl, cyclohexanecarbonyl, adamantanecarbonyl, and the like, or from a benz-fused monocyclic cycloalkanecarboxylic acid which is optionally substituted by, for example, alkanoylamino, such as 1,2,3,4-tetrahydro-2-naphthoyl, 2-acetamido-1,2,3,4-tetrahydro-2-naphthoyl. The term xe2x80x9caralkanoylxe2x80x9d means an acyl radical derived from an aryl-substituted alkanecarboxylic acid such as phenylacetyl, 3-phenylpropionyl(hydrocinnamoyl), 4-phenylbutyryl, (2-naphthyl)acetyl, 4-chlorohydrocinnamoyl, 4-aminohydrocinnamoyl, 4-methoxyhydrocinnamoyl, and the like. The term xe2x80x9caroylxe2x80x9d means an acyl radical derived from an aromatic carboxylic acid. Examples of such radicals include aromatic carboxylic acids, an optionally substituted benzoic or naphthoic acid such as benzoyl, 4-chlorobenzoyl, 4-carboxybenzoyl, 4-(benzyloxycarbonyl)benzoyl, 1-naphthoyl, 2-naphthoyl, 6-carboxy-2 naphthoyl, 6-(benzyloxycarbonyl)-2-naphthoyl, 3 -benzyloxy-2-naphthoyl, 3-hydroxy-2-naphthoyl, 3-(benzyloxyformamido)-2-naphthoyl, and the like. The heterocyclyl or heterocycloalkyl portion of a heterocyclylcarbonyl, heterocyclyloxycarbonyl, heterocyclylalkoxycarbonyl, or heterocyclyalkyl group or the like is a saturated or partially unsaturated monocyclic, bicyclic or tricyclic heterocycle which contains one or more hetero atoms selected from nitrogen, oxygen and sulphur, which is optionally substituted on one or more carbon atoms by halogen, alkyl, alkoxy, oxo, and the like, and/or on a secondary nitrogen atom (i.e., xe2x80x94NHxe2x80x94) by alkyl, aralkoxycarbonyl, alkanoyl, phenyl or phenylalkyl or on a tertiary nitrogen atom (i.e.xe2x95x90Nxe2x80x94) by oxido and which is attached via a carbon atom. The heteroaryl portion of a heteroaroyl, heteroaryloxycarbonyl, or a heteroaralkoxy carbonyl group or the like is an aromatic monocyclic, bicyclic, or tricyclic heterocycle which contains the hetero atoms and is optionally substituted as defined above with respect to the definition of heterocyclyl. Such heterocyclyl and heteroaryl radicals have from four to about 12 ring members, preferably from 4 to 10 ring members. Examples of such heterocyclyl and heteroaryl groups are pyrrolidinyl, piperidinyl, piperazinyl, morpholinyl, thiamorpholinyl, pyrrolyl, imidazolyl (e.g., imidazol 4-yl, 1-benzyloxycarbonylimidazol-4-yl, etc.), pyrazolyl, pyridyl, pyrazinyl, pyrimidinyl, furyl, thienyl, triazolyl, oxazolyl, thiazolyl, indolyl (e.g., 2-indolyl, etc.), quinolinyl, (e.g., 2-quinolinyl, 3-quinolinyl, 1-oxido-2-quinolinyl, etc.), isoquinolinyl (e.g., 1-isoquinolinyl, 3-isoquinolinyl, etc.), tetrahydroquinolinyl (e.g., 1,2,3,4-tetrahydro-2-quinolyl, etc.), 1,2,3,4-tetrahydroisoquinolinyl (e.g., 1,2,3,4-tetrahydro-1-oxo-isoquinolinyl, etc.), quinoxalinyl, xcex2-carbolinyl, 2-benzofurancarbonyl, 1-,2-,4- or 5-benzimidazolyl, and the like. The term xe2x80x9ccycloalkylalkoxycarbonylxe2x80x9d means an acyl group derived from a cycloalkylalkoxycarboxylic acid of the formula cycloalkylalkyl-Oxe2x80x94COOH wherein cycloalkylalkyl has the significance given above. The term xe2x80x9caryloxyalkanoylxe2x80x9d means an acyl radical of the formula aryl-O-alkanoyl wherein aryl and alkanoyl have the significance given above. The term xe2x80x9cheterocyclyloxycarbonylxe2x80x9d means an acyl group derived from heterocyclyl-Oxe2x80x94COOH wherein heterocyclyl is as defined above. The term xe2x80x9cheterocyclylalkanoylxe2x80x9d is an acyl radical derived from a heterocyclyl-substituted alkane carboxylic a wherein heterocyclyl has the significance given above. The term xe2x80x9cheterocyclylalkoxycarbonylxe2x80x9d means an acyl radical derived from a heterocyclyl-substituted alkane-Oxe2x80x94COOH wherein heterocyclyl has the significance given above. The term xe2x80x9cheteroaryloxycarbonylxe2x80x9d means an acyl radical derived from a carboxylic acid represented by heteroaryl-Oxe2x80x94COOH wherein heteroaryl has the significance given above. The term xe2x80x9caminocarbonylxe2x80x9d alone or in combination, means an amino-substituted carbonyl (carbamoyl) group derived from an amino-substituted carboxylic acid wherein the amino group can be a primary, secondary or tertiary amino group containing substituents selected from hydrogen, and alkyl, aryl, aralkyl, cycloalkyl, cycloalkylalkyl radicals and the like. The term xe2x80x9caminoalkanoylxe2x80x9d means an acyl group derived from an amino-substituted alkanecarboxylic acid wherein the amino group can be a primary, secondary or tertiary amino group containing substituents selected from hydrogen, and alkyl, aryl, aralkyl, cycloalkyl, cycloalkylalkyl radicals and the like. The term xe2x80x9chalogenxe2x80x9d means fluorine, chlorine, bromine or iodine. The term xe2x80x9chaloalkylxe2x80x9d means an alkyl radical having the significance as defined above wherein one or more hydrogens are replaced with a halogen. Examples of such haloalkyl radicals include chloromethyl, 1-bromoethyl, fluoromethyl, difluoromethyl, trifluoromethyl, 1,1,1-trifluoroethyl and the like. The term xe2x80x9cleaving groupxe2x80x9d generally refers to groups readily displaceable by a nucleophile, such as an amine, a thiol or an alcohol nucleophile. Such leaving groups are well known in the art. Examples of such leaving groups include, but are not limited to, N-hydroxysuccinimide, N-hydroxybenzotriazole, halides, triflates, tosylates and the like. Preferred leaving groups are indicated herein where appropriate.
Procedures for preparing fine compounds of Formula I are set forth below. It should be noted that the general procedure is shown as it relates to preparation of compounds having the specified stereochemistry, for example, wherein the absolute stereochemistry about the hydroxyl group is designated as (R), which is the preferred stereochemistry for the compounds of the present invention. However, such procedures are generally applicable to those compounds of opposite configuration, e.g., where the stereochemistry about the hydroxyl group is (S). In addition, the compounds having the (R) stereochemistry can be utilized to produce those having the (S) stereochemistry. For example, a compound having the (R) stereochemistry can be inverted to the (S) stereochemistry using well-known methods.
The compounds of the present invention represented by Formula I above can be prepared utilizing the following general procedure. This procedure is schematically shown in the following Schemes I and II: 
An N-protected chloroketone derivative of an amino acid having the formula: 
wherein P represents an amino protecting group, and R2 is as defined above, is reduced to the corresponding alcohol utilizing an appropriate reducing agent. Suitable amino protecting groups are well known in the art and include carbobenzoxy, t-butoxycarbonyl, and the like. A preferred amino protecting group is carbobenzoxy. A preferred N-protected chloroketone is N-benzyloxycarbonyl-L-phenylalanine chloromethyl ketone. A preferred reducing agent is sodium borohydride. The reduction reaction is conducted at a temperature of from xe2x88x9210xc2x0 C. to about 25xc2x0 C., preferably at about 0xc2x0 C., in a suitable solvent system such as, for example, tetrahydrofuran, and the like. The N-protected chloroketones are commercially available, e.g., such as from Bachem, Inc., Torrance, Calif. Alternatively, the chloroketones can be prepared by the procedure set forth in S. J. Fittkau, J. Prakt. Chem., 35, 1037 (1973), and subsequently N-protected utilizing procedures which are well known in the art.
The halo alcohol can be utilized directly, as described below, or, preferably, is then reacted, preferably at room temperature, with a suitable base in a suitable solvent system to produce an N-protected amino epoxide of the formula: 
wherein P and R2 are as defined above. Suitable solvent systems for preparing the amino epoxide include ethanol, methanol, isopropanol, tetrahydrofuran, dioxane, and the like including mixtures thereof. Suitable bases for producing the epoxide from the reduced chloroketone include potassium hydroxide, sodium hydroxide, potassium t-butoxide, DBU and the like. A preferred base is potassium hydroxide.
Alternatively, a protected amino epoxide can be prepared starting with an L-amino acid which is reacted with a suitable amino-protecting group in a suitable solvent to produce an amino-protected L-amino acid ester of the formula: 
wherein P1 and P2 independently represent hydrogen, benzyl and amino-protecting groups (as defined above), provided that P1 and P2 are not both hydrogen; P3 represents carboxyl-protecting group, e.g., methyl, ethyl, benzyl, tertiary-butyl and the like; and R2 is as defined above.
The amino-protected L-amino acid ester is then reduced, to the corresponding alcohol. For example, the amino-protected L-amino acid ester can be reduced with diisobutylaluminum hydride at xe2x88x9278xc2x0 C. in a suitable solvent such as toluene. The resulting alcohol is then converted, for example, by way of a Swern oxidation, to the corresponding aldehyde of the formula: 
wherein P1, P2 and R2 are as defined above. Thus, a dichloromethane solution of the alcohol is added to a cooled (xe2x88x9275 to xe2x88x9268xc2x0 C.) solution of oxalyl chloride in dichloromethane and DMSO in dichloromethane and stirred for 35 minutes.
The aldehyde resulting from the Swern oxidation is then reacted with a halomethyllithium reagent, which reagent is generated in situ by reacting an alkyllithium or arylithium compound with a dihalomethane represented by the formula X1CH2X2 wherein X1 and X2 independently represent I, Br or Cl. For example, a solution of the aldehyde and chloroiodomethane in THF is cooled to xe2x88x9278xc2x0 C. and a solution of n-butyllithium in hexane is added. The resulting product is a mixture of diastereomers of the corresponding amino-protected epoxides of the formulas: 
The diastereomers can be separated e.g., by chromatography, or, alternatively, once reacted in subsequent steps the diastereomeric products can be separated. For compounds having the (S) stereochemistry, a D-amino acid can be utilized in place of the L-amino acid.
The amino epoxide is then reacted, in a suitable solvent system, with an equal amount, or preferably an excess of, a desired amine of the formula:
R3NH2
wherein R3 is hydrogen or is as defined above. The reaction can be conducted over a wide range of temperatures, e.g., from about 10xc2x0 C. to about 100xc2x0 C., but is preferably, but not necessarily, conducted at a temperature at which the solvent begins to reflux. Suitable solvent systems include protic, non-protic and dipolar aprotic organic solvents such as, for example, those wherein the solvent is an alcohol, such as methanol, ethanol, isopropanol, and the like, ethers such as tetrahydrofuran, dioxane and the like, and toluene, N,N-dimethylformamide, dimethyl sulfoxide, and mixtures thereof. A preferred solvent is isopropanol. Exemplary amines corresponding to the formula R3NH2 include benzyl amine, isobutylamine, n-butyl amine, isopentyl amine, isoamylamine, cyclohexanemethyl amine, naphthylene methyl amine and the like. The resulting product is a 3-(N-protected amino)-3-(R2)-1-(NHR3)-propan-2-ol derivative hereinafter referred to as an amino alcohol) can be represented by the formulas: 
wherein P, P1, P2, R2 and R3 are as described above. Alternatively, a haloalcohol can be utilized in place of the amino epoxide.
The amino alcohol defined above is then reacted in a suitable solvent with a sulfamoyl halide, e.g. sulfamoyl chloride (R4R5NSO2Cl or R4HNSO2Cl) or sulfamoyl anhydride in the presence of an acid scavenger. Suitable solvents in which the reaction can be conducted include methylene chloride, tetrahydrofuran. Suitable acid scavengers include triethylamine, pyridine. The resulting sulfamic acid derivative can be represented, depending on the epoxide utilized, by the formulas; 
wherein P, P1, P2, R2, R3, R4 and R5 are as defined above. These intermediates are useful for preparing inhibitor compounds of the present invention and are also active inhibitors of retroviral proteases.
The sulfamoyl halides of the formula R4NHSO2X can be prepared by the reaction of a suitable isocyanate of the formula R4NCO with fuming sulfuric acid to produce the corresponding sulfamate which is then converted to the halide by well known procedures, such as by treating the sulfamate with PCl5. Alternatively the isocyanate can be treated with chlorosulfonic acid to produce the corresponding sulfamoyl chloride directly.
The sulfamoyl halides of the formula R4R5NSO2Cl can be prepared by reacting an amine of the formula R4R5NH, preferably as a salt such as the hydrochloride, with sulfuryl chloride in a suitable solvent such as acetonitrile. The reaction mixture is gradually warmed to reflux temperature and maintained at the reflux temperature until the reaction is complete. Alternatively, sulfamoyl halides of the formula R4R5NSO2Cl can be prepared by reacting an amine of the formula R4R5NH with sulfuryl chloride in boiling MeCN as disclosed in Matier et al., J. Med. Chem., 15, No. 5, p.538 (1972).
Following preparation of the sulfamic acid derivative, the amino protecting group P or P1 and P2 amino protecting groups are removed under conditions which will not affect the remaining portion of the molecule. These methods are well known in the art and include acid hydrolysis, hydrogenolysis and the like. A preferred method involves removal of the protecting group, e.g., removal of a carbobenzoxy group, by hydrogenolysis utilizing palladium on carbon in a suitable solvent system such as an alcohol, acetic acid, and the like or mixtures thereof. Where the protecting group is a t-butoxycarbonyl group, it can be removed utilizing an inorganic or organic acid, e.g., HCl or trifluoroacetic acid, in a suitable solvent system, e.g., dioxane or methylene chloride. The resulting product is the amine salt derivative. Following neutralization of the salt, the amine is then reacted with an amino acid or corresponding derivative thereof represented by the formula (PN[CR1xe2x80x2 R1xe2x80x3]t CH(R1)COOH) wherein t, R1, R1xe2x80x2 and R1xe2x80x3 are as defined above, to produce the antiviral compounds of the present invention having the formula: 
wherein t, P, R1, R1xe2x80x2, R1xe2x80x3, R2, R3, R4 and R5 are as defined above. Preferred protecting groups in this instance are a benzyloxycarbonyl group or a t-butoxycarbonyl group. Where the amine is reacted with a derivative of an amino acid, e.g., when t=1 and R1xe2x80x2 and R1xe2x80x3 are both H, so that the amino acid is a xcex2-amino acid, such xcex2-amino acids can be prepared according to the procedure set forth in a copending application, U.S. Ser. No. 07/345,808. Where t is 1, one of R1xe2x80x2 and R1xe2x80x3 is H and R1 is hydrogen so that the amino acid is a homo-xcex2-amino acid, such homo-xcex2-amino acids can be prepared by the procedure set forth in a copending application, U.S. Ser. No. 07/853,561. Where t is O and R1 is alkyl, alkenyl, alkynyl, cycloalkyl, xe2x80x94CH2SO2NH2, xe2x80x94CH2CO2CH3, xe2x80x94CO2CH3, xe2x80x94CONH2, xe2x80x94CH2C(O)NHCH3, xe2x80x94C(CH3)2(SH), xe2x80x94C(CH3)2(SCH3), xe2x80x94C(CH3)2[S(O)CH3], xe2x80x94C(CH3)2[S(O2)CH3], or an amino acid side chain, such materials are well known and many are commercially available from Sigma-Aldrich.
The N-protecting group can be subsequently removed, if desired, utilizing the procedures described above, and then reacted with a carboxylate represented by the formula: 
wherein R is as defined above and L is an appropriate leaving group such as a halide. Preferably, where R1 is a side chain of a naturally occurring xcex1-amino acid, R is a 2-quinoline carbonyl group derived from N-hydroxysuccinimide-2-quinoline carboxylate, i.e., L is hydroxy succinimide. A solution of the free amine (or amine acetate salt) and about 1.0 equivalent of the carboxylate are mixed in an appropriate solvent system and optionally treated with up to five equivalents of a base such as, for example, N-methylmorpholine, at about room temperature. Appropriate solvent systems include tetrahydrofuran, methylene chloride or N,N:-dimethylformamide, and the like, including mixtures thereof.
Alternatively, the protected amino alcohol from the epoxide opening can be further protected at the newly introduced amino group with a protecting group Pxe2x80x2 which is not removed when the first protecting P is removed. One skilled in the art can choose appropriate combinations of P and Pxe2x80x2. One suitable choice is when P is Cbz and Pxe2x80x2 is Boc. The resulting compound represented by the formula: 
can be carried through the remainder of the synthesis to provide a compound of the formula: 
and the new protecting group Pxe2x80x2 is selectively removed, and following deprotection, the resulting amine reacted to form the sulfamic acid derivative as described above. This selective deprotection and conversion to the sulfamic acid can be accomplished at either the end of the synthesis or at any appropriate intermediate step if desired.
It is contemplated that for preparing compounds of the Formulas having R6, the compounds can be prepared following the procedure set forth above and, prior to coupling the sulfonamide derivative or analog thereof, e.g. coupling to the amino acid PNH(CH2)tCH(R1)COOH, carried through a procedure referred to in the art as reductive amination. Thus, a sodium cyanoborohydride and an appropriate aldehyde or ketone can be reacted with the sulfonamide derivative compound or appropriate analog at room temperature in order to reductively aminate any of the compounds of Formulas I-IV. It is also contemplated that where R3 of the amino alcohol intermediate is hydrogen, the inhibitor compounds of the present invention wherein R3 is alkyl, or other substituents wherein the xcex1-C contains at least one hydrogen, can be prepared through reductive amination of the final product of the reaction between the amino alcohol and the amine or as any other stage of the synthesis for preparing the inhibitor compounds.
Contemplated equivalents of the general formulas set forth above for the antiviral compounds and derivatives as well as the intermediates are compounds otherwise corresponding thereto and having the same general properties, such as tautomers thereof as well as compounds, wherein one or more of the various R groups are simple variations of the substituents as defined herein, e.g., wherein R is a higher alkyl group than that indicated. In addition, where a substituent is designated as, or can be, a hydrogen, the exact chemical nature of a substituent which is other than hydrogen at that position, e.g., a hydrocarbyl radical or a halogen, hydroxy, amino and the like functional group, is not critical so long as it does not adversely affect the overall activity and/or synthesis procedure.
The chemical reactions described above are generally disclosed in terms of their broadest application to the preparation of the compounds of this invention. Occasionally, the reactions may not be applicable as described to each compound included within the disclosed scope. The compounds for which this occurs will be readily recognized by those skilled in the art. In all such cases, either the reactions can be successfully performed by conventional modifications known to those skilled in the art, e.g., by appropriate protection of interfering groups, by changing to alternative conventional reagents, by routine modification of reaction conditions, and the like, or other reactions disclosed herein or otherwise conventional, will be applicable to the preparation of the corresponding compounds of this invention. In all preparative methods, all starting materials are known or readily preparable from known starting materials.
Without further elaboration, it is believed that one skilled in the art can, using the preceding description, utilize the present invention to its fullest extent. The following preferred specific embodiments are, therefore, to be construed as merely illustrative, and not limitative of the remainder of the disclosure in any way whatsoever.
The following Examples 1 through 9 illustrate preparation of intermediates. These intermediates are useful in preparing the inhibitor compounds of the present invention as illustrated in Examples 13-17. In addition, the intermediates of Examples 4-9 are also retroviral protease inhibitors and inhibit, in particular, HIV protease.